Mathematics GCSE Revision Session
Mr John Casey
BEng (Hons) PGCE
Mathematics Teacher
Pentrehafod School, Swansea
Solving Simultaneous Equations
Mathematics GCSE Revision Session
Session 1: Solving linear equations
Session 2: Solving simultaneous equations
Session 3: Percentages (Non-Calculator)
Session 4: Percentages (Calculator)
Session 5 (Live Session): Recap of sessions 1 – 4
Wednesday 25th October 5.15pm – 6pm??
Linear Equations
Solve the equations:
1) 9y – 4 = 23 2) 4(4a – 7) = -92 3) 2(4m + 3) = 24m – 2
Topics being covered today:
Equations
2x + 8 = 15
Linear equation
Has one unknown
4x + 5y = 15
Simultaneous equations
Has two unknowns
7x + 2y = 36
Example 1 - Adding
Solve the equations:
2x – 3y = 0
4x + 3y = 18
Example 2 - Adding
Solve the equations:
x + 2y = 7
-x + 4y = 5
Example 3 - Subtracting
Solve the equations:
5x + 2y = 80
3x + 2y = 70
Try these
Solve the equations:
6x + 2y = 6
x – 2y = 8
2x – 3y = 5
2x + 4y = 12
Example 4 – Different Coefficients
Solve the equations:
3m + 2n = 20
2m + 5n = 17
Try this
Solve the equations:
6h – 5d = 38
5h – 3d = 27
Example 5 – Problem Solving
The rectangle has a perimeter of 30cm and the triangle has a perimeter of 21cm. Form and solve the equations and calculate the value of x and y.
3x
y
3x
2x
x – y
GCSE
Questions
GCSE Question 1
GCSE Question 2
GCSE Question 3
[3]
Topics being covered today:
Plenary
Fill in the blanks:
Check the ___________ are the same for one variable before adding or subtracting the equations.
If the signs are the same, you ____________.
If the signs are different, you ____________.
Once you have found one variable, you ____________ to find the second variable.
To check the answers are correct, you could ____________ into the original equations.
Key words
Simultaneous
Equations
Solve
Coefficients
Substitute
Variable
Add
Subtract
Multiply